


Bloody, Covetous Creatures

by JacarandaBanyan



Category: Naruto
Genre: Alternate Universe, Alternate Universe - Fantasy, Bingo, Blood and Violence, Corrupt Government Official!Kakuzu, Developing Relationship, Imprisonment, KakuHida Discord Server Bingo, Kakuzu covets Hidan and Hidan lusts after Kakuzu, M/M, Merpeople, Pre-Relationship, Prompt Fill, Sirens, Unhealthy Relationships, Violence, mermaid au, mermaid!Hidan
Language: English
Status: Completed
Published: 2019-03-06
Updated: 2019-03-06
Packaged: 2019-11-12 21:28:03
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 1
Words: 4,231
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18018776
Author URL: https://archiveofourown.org/users/JacarandaBanyan/pseuds/JacarandaBanyan
Summary: When Kakuzu learned that sirens and their body parts went for big money on the black market, he attempted to kill one that came hunting for sailors near his ship.





	Bloody, Covetous Creatures

**Author's Note:**

> My first fill for the KakuHida Discord Bingo.  
> Square: Merpeople AU

The ship had been sailing through the mist for about an hour when the crew members first heard the song. It came softly at first, so softly and far away that it had no power over the sailors. People rushed up from down below, some of them wrapped up in blankets to ward off the mists’ chill, clearly fresh from their bunks. Chatter raced up and down the deck as the crew began to chitter like a flock of birds disturbed by a hint of danger. 

They spoke in Water Dialect, with accents thick enough to peel the vessel’s new paint job, so Kakuzu stood like a stone amid the sudden flurries of activity, blood pressure slowly rising. 

He was not here to deal with sailors’ superstitions, and strange songs from the sea were none of his concern. Nor were they the concern of the crew. Their only objective was to deliver the rice crop from the south to the capital, and Kakuzu’s only objective was to use the ship to smuggle foreign silver (acquired from shady characters in well-lit establishments near the southernmost port of Taki, where pirates kept the peace more effectively than the government) past the custom houses. He didn’t care if it was the melodic cries of one of the Court ’s precious singers as they drowned- unless there was money to be made, it was no business for a merchant ship. 

One of the more senior crew members finally realized that the wealthy bureaucrat was getting ready to snap and pulled him aside with profuse apologies and much hand-wringing. 

“My sincerest regrets, sir,” the man stammered, “but I must advise you to go below for your own safety.”

Kakuzu glared at the rapidly gathering crowd near the railings. The man winced. 

“Yes, well. The crew, you see, they’ve done this route many times before, and it is your first time joining us.” The man’s tone made it clear that he still wondered what an honored government official was doing auditing a routine state-sponsored crop shipment instead of dealing with the growing pirate problem in the south, where he was officially stationed. Kakuzu didn’t deign to speak, letting the silence grow heavier and heavier until the man broke beneath it. 

“Well. These waters, they can be… dangerous for those who have not sailed them before. Shoals, strange currents, islands that submerge at high tide, it’s truly an honest sailor’s nightmare. And that’s not to mention the creatures that swim here.”

“What _creatures?”_ Kakuzu growled. If these men were getting all riled up over a dolphin or some such thing, he would definitely be including it in his official report to the capital. He had enough clout to get these men kicked off this lucrative, highly coveted assignment. There were plenty of others who would jump at the chance to crew a state vessel. And would probably do it for less pay, too. 

The man winced. 

“There are several creatures that have been known to come close to ships that pass this way, or who make their homes near critical junctures. We’re approaching Obito’s Wreck now, and the song means that the sirens will be out in full force when we get there. This far away their songs won’t do much, so the men want to listen while their heads are still clear. Before long though they’ll have to put in earplugs or lash themselves to something, or they’ll go mad and jump overboard. If anyone does that, the sharks will be following us for days. Sirens are vicious things, you know.”

The man shuddered, as though the mere thought of sirens sent ice down his spine. Kakuzu was not impressed. 

Sirens, huh? He vaguely remembered hearing about them from one of the pirates he regularly cut deals with. Near impossible to catch and extremely dangerous, but the few that had been caught had fetched an astronomical price on the black market or been bought up for still higher amounts by the wealthiest Court members. Even their body parts fetched huge sums. 

Kakuzu smiled slightly behind his face mask and loosened his ceremonial (yet still deadly sharp) sabre in its sheath.

* * *

Slowly, the crew retreated below or began lashing each other with long tethers to the mast or some other sturdy part of the ship. They left just enough rope for the sailors to still move about the deck, doing their various duties to keep the vessel sailing forward, but not enough to stretch overboard. The first mate emerged from his stateroom with a bucket full of some wax for the men to stick into their ears. Kakuzu took a pair, though he didn’t take as much care as some of the crew in applying them. He saw no need to completely deafen himself, so long as he blocked out the song.

The man from before tried several times to convince Kakuzu to go below, but Kakuzu had long years of experience dealing with spineless jellyfish like him. His words slid off him like water over a stone. 

At long last, the ghostly wreckage of Obito Uchiha’s infamous trading ship began to appear through the mist like a fiendish specter. The deck had fallen silent; the crew had coordinated and confirmed all of their duties and the landmarks to steer for before sealing off their ears. The water was still and flat as a sheet of ice. 

As they drew closer and closer, the ghostly shadow of the wreckage began to take more concrete shape. It was not an easy sight. The hull was warped and split on an enormous rock, leaving both halves at opposite angles on either side. Barnacles, seaweed, and all manner of the sea’s principle colonizers coated the sides, disguising how low the wreck sat in the water. The mast was snapped like a match struck too hard, wicked splinters pointing straight up. Rope and sail had long since begun rotting, but their corpses still hung from the ship like tattered clothes. Kakuzu shuttered to think of the financial loss it represented. 

The ship and the rocks that held it in place were covered in figures that from a great enough distance and with a thick enough fog could be mistaken for seals. Closer up, their lovely scaled mermaid tails became visible against the dull grey of the rocks, and their teeth gleamed like well-polished knives in the ship’s light. Before Kakuzu’s eyes, several of them dove from the ruined decks or slipped from the rocks into the water and became indistinct, dark shapes under the surface. 

The ones that had not, however, had their mouthes opened in song. 

Kakuzu hadn’t imagined that such deadly predators could make such sweet music filled with such pure yearning. It wasn’t that he hadn’t expected their voices to be talented enough to lure men to their deaths- the crew maybe stupid, superstitious commoners, but they had sailed this route many times before. He’d just expected something darker, something sultry and sinful. Not this beautiful sound. 

Without even thinking about it, his hands began to remove his already-loose earplugs. He had not been lashed down- none of the crew dared approach someone so high above their rank and with so much power over their continued employment. One of the mates had simply handed him a rope and told him to lash himself to something if he insisted on not going below. Kakuzu had not deigned to listen to him. He was not so undisciplined as to leap to his own death for a pretty face and a clever tongue. 

The railing was damp with condensed mist under his fingers- when had he walked to the railing?- and he removed his gloves and stuffed them in his pocket. He had spares in his stateroom. No need to ruin them with saltwater or blood if a siren got too close. He removed his saber from his scabbard, and patted his waist sheath to make sure his hidden knife was still safely strapped under his coat, in easy grabbing range. 

The number of dark shapes beneath the ship grew and grew, and some of the sirens began to surface, singing as they swam directly alongside the ship. From this close up, he could see the way their delicate tongues danced between their gory, horrifying teeth. Those tongues would be worth so much if he could just cut one out. More than enough to cover any medical expenses he incurred. Those teeth were deadly, yes, but they’d be hard pressed to kill him with a single bite. 

One siren in particular caught his eye. It had the face of a young man, with eyes the bright purple of the rich, expensive velvet imported from the west, and hair the color of the silver Kakuzu hid in his stateroom, sewn into his already heavy ceremonial clothing and stashed in his personal luggage. 

It swam alongside the ship, sometimes propelling itself out of the water with its long tail and scratching at the sides. It never reached the lifelines, never even gets close, but it kept doing it anyway. 

Slowly, the ship began to make the turn around the point, leaving the wreck behind them, and the sirens began to swim back to the rocks where their fellows lounged, disappointed. These sailors weren’t going to leap to their deaths, so there was no point chasing them. 

The song, though, continued, setting Kakuzu’s blood to singing. It lured him, lulled him, begged him, spun stories of endless wealth, enough silver to build his own palace. He just needed to get a piece of one, and he’d be set for life. 

He jumped. 

The water shocked him on impact, but he pushed past it. The ship was moving slowly, and the wreck was still easily in swimming distance. He just needed to reach it. His arms pulled quickly through the water and his legs kicked powerfully. The heat of muscles kicked into overdrive kept him warm enough to keep swimming. 

The sirens were further away than he’d thought, and he felt his body begin to protest, but the singing lent him the strength he needed to keep swimming. 

The voice grew more and more brilliant as he swam closer, until the glorious promise of it filled his vision like a spotlight in the dark. The water pulled at his aching muscles, trying to pull him down, down where he couldn’t hear those sweetly sung promises of wealth and power and plenty, but he was stronger than the current. Life fighting pirates and working in the dirtier, harder parts of the world where bureaucrats usually never set foot had hardened his already powerful muscles, and the sea frothed in vain. Cold vibrated against his skin like a bell, trying and failing to pierce the ever-replenishing heat of exertion.

His hand struck stone with a painful smack. 

Kakuzu grinned and pulled himself through the slick, barnacle-encrusted rocks, uncaring of how he cut up his palms in his enthusiasm. His blood spilled into the current like oil. 

Suddenly, his vision was filled with silver, and the siren from before was on him, bony fingers clutching his arm and teeth bared. The siren was strong, strong enough to pull Kakuzu under the water. He thrust out with his sabre, and for a second the sweet song was interrupted by a shriek of pain. It reverberated through the water like a struck bell. The vibrations pierced his skull, nearly making him drop his weapon. It broke the compulsion the singing had wrought upon him, but his greed urged him on in its stead. 

The hand clenched tighter around his bicep, so tightly that the flesh there throbbed in pain. He ignored it. He’d drawn siren blood, and he intended to draw more. The song confused him, making him blind to the school of sirens swimming a few short seconds swim away, watching with hungry eyes as one of their own took down this unexpected prey. All he saw was the sword slash through the siren’s silvery-white skin. The song twined together with his greed, adrenaline and battlelust to the exclusion of all else. 

The siren struck again, quick as lightning, this time going for his powerful, treading legs. It clearly hoped to cripple him. Kakuzu had seen that move too many times from pirates who thought they could deal with him at sword point rather than over the negotiating table, and he was ready for it. He sliced the creature again even as its teeth slid over his skin. It didn’t manage to bite, but his skin split and began to bleed anyway. 

The siren shot him a look of delight and derangement. 

It attacked his sword arm next. Kakuzu anticipated this too, and used the opportunity to thrust his whole sabre through the creature’s lovely tail, just below it’s muscled stomach. It was difficult, forcing the blade through muscle and sinew, especially when his own muscles were screaming for air, but he pushed hard and the sharpened blade slid home. The siren’s forward momentum kept it moving all the way down the length of the blade, and it sank it’s teeth into his shoulder. He clenched his teeth to keep from screaming and letting what precious little air was left in his lungs escape. He had mortally wounded it. All he had to do now was get to the surface. 

When the siren pulled back, it wrenched his sabre from hand, but it was no matter. It was dead in the water. He swam after it and swiped at its trailing fin. It felt slippery in his palm, but he had handled fish before. That alone wouldn’t make him loose his grip. He dug his nails in deep and began kicking towards the surface. There was a beach just beyond the rocks, if he remembered his maps correctly. The ship turned and hugged the beach for several miles in order to avoid a series of shoals before reaching deeper water again. He could get on one of the rocks and catch his breath, then drag the corpse ashore and get to higher, safer land. He could signal the ship with a fire on the far beach, where the ship undoubtedly stopped once they realized he’d jumped. It was out of sight of the wreck, so they would be somewhat safe from the sirens. 

He broke the surface with a gasp. Air burned its way down his throat. He gulped down oxygen as fast as he could, gasping old, dead air only when his full lungs demanded he do so in order to allow more air in. The air like an electric tingle as it hit his bloodstream. 

Then there was a sharp pain in his ankle.

He still held the end of the siren’s fin in his hand, pulling and jerking wildly though it was, so it took a few seconds for his under-oxygenated brain to realize what had happened. The siren hadn’t bleed out yet, and he was holding it upside down. If it tried, it could bend around and bite him. It would be painful for it to engage its core torso muscles, and would increase the bleeding, but it could do it. He gripped the tail harder, so hard that his nails broke the strange skin and it began to bleed lightly in between his fingers. 

Another sharp pain shot up from the same ankle. It felt like his foot was being ripped off. He kicked out sharply, hoping to hit the creature’s head. He didn’t connect with anything. It was becoming painful to tread water with his injured foot. 

The next bite sank into the back of his calf, and the pain caused him to finally let go of the tail. 

In an instant he was pulled under the surface again. His eyes stung if he opened them too much in the salty, dirty water, but he slitted them open as far as he could let them, looking around for the siren. 

It hovered in the water several feet to his left, wild eyed and bleeding heavily. A little too heavily, in fact- at this rate, it should have lost consciousness already. But its powerful tail undulated through the water just as powerfully, and when it lunged at him it moved with the same grace and speed as before. His surprise cost him a vital second and the siren scored another bite, this time to his uninjured shoulder. This time it latched on, twisting its teeth and trying to dig them deeper into the flesh there. 

He reached into his belt and yanked out his knife with one hand while the other one tried in vain to push the creature off him. It took him a few fumbled heartbeats, but the moment the blade slid free of its sheath he plunged it into the siren’s throat. It shrieked again, and darted away from him again. 

As it swam away, he noticed that its injuries were healing. His sword slashes were beginning to close up, and the hole in its belly no longer bled like a fountain. 

He needed to get out of the water, as soon as possible, or this thing was going to outbleed him. But first he needed to cut off a piece. Just one piece. 

It lunged again. His knife flashed out, and as the blade bit into the siren’s tongue it’s teeth sank into his hand. It screeched and tried to back up, but Kakuzu kept moving through the pain. He tightened his grip on the handle and sawed deeper, putting more and more pressure on until he felt the muscle give. Only then did he let up.

The siren retreated several feet, and Kakuzu held its bleeding tongue in his grasp. 

The song was completely gone from the water now, and if he was paying more attention to his surroundings he would have seen that the other sirens had swum away, back to their comfortable perches on the wreck and the rocks. His silver haired siren was the only one still facing him, blood spilling from its mouth in place of sweet music, and surely it would flee now too. It had lost that most precious organ, the instrument of its otherworldly music. What creature would risk losing even more? The flesh was warm in his hand, like freshly printed money, and his brain was so low on oxygen that everything, even the creature’s gory maw, looked beautiful. He didn’t need the sirens’ song to urge him on. His greed was motivation enough. 

He turned his face upward and began to swim towards the light. It looked so close, just an easy couple of strokes away. His heart was so thoroughly convinced of the closeness of the surface that it didn’t pound and waste what little air he still had. 

But no matter how many strokes he took, that shimmering light didn’t get any closer. 

The thought penetrated the fog in his mind slowly. Why wasn’t he rising? The light should have gotten brighter and brighter until finally he had to shut his eyes as he broke the surface, but it was getting dimmer and greener instead. He tightened his grip on the tongue, and began kicking and pulling at the water with more urgency. As he did this, he found that there was a weight on his left foot, making it difficult to kick. 

His sight grew dark, and his thoughts more jumbled and chaotic. Effects didn’t have causes, his sentences never reached their conclusions, and the siren was still there, still grinning its hyena grin. In the water around them, its blood mixed with his and the light faded away to nothing.

* * *

When Kakuzu woke, it was dark, but not as dark as the bottom of the ocean. He rubbed the saltiness from his eyes and peered around him.

He was sitting on a rock in a space several meters wide. More smooth rocks formed a most of the floor, but to his left was a sizable drop off into bottomless water. Small crab-like creatures scuttled about, occasionally glowing blue or green or silver. Coral-like plants, hairy tubes, sea anemones and trailing, hair-like sea weed grew from the walls, making the space pulse with life. Some of these glowed too. Tiny fish flashed silver as the darted about the water. Lit by the soft glowing were heaps of gold and silver coins, ornate chalices, delicate china sporting cracks and holes, intricately carved fine ivory combs, tiaras, gem stones, glittering, heavy jewelry- a horde of treasure fit for a dragon. Some of it had barnacles growing over it, or crustaceans tapping their pointed little feet on their precious surfaces, wile some of silver gleamed like it was smelted just yesterday. 

Perched on a pile of it, fin trailing in the water, was the silver siren. It grinned when it saw that he was awake, and used its arms to drag itself down the mountain of gold coins, causing a minor landslide. Some of them _plonked_ into the water and sank out of sight. The siren didn’t seem to notice. Dried blood was streaked down the creature’s chin and throat like a grotesque beard. The deep scarlet of it stood out against its silvery pale skin. 

Sitting among the riches, tempting body spread out and on display, and with the echoes of it’s sweet, sweet song still ringing in his ears, it had the nerve to be _beautiful._ Even as he drew away in disgust at the copious blood, another part of him responded as he always did to lust, greed, and temptation. 

“Hello sailor,” it said, and with a flash of horror Kakuzu realized that its tongue had grown back, or taken it back from Kakuzu’s unconscious body. “You’re such a shitty swimmer. It’s cute to watch your stupid fucking face as you run out of air and realize your time on earth is over.”

Kakuzu’s hand clenched, and a trickle of blood answered him, like the last water wrung from a wet rag. He still had this thing’s tongue.

“You fought better than you swam, not that that’s too fucking hard,” it continued. Its voice was sweet and lilting, echoes of a powerful song in each word. “And each fucking cut hurt like a bitch. After dragging you here, I was able to absolutely drench Jashin-sama in blood.”

Kakuzu followed its eyes and nearly choked on his next breath. There, nestled among the gold and jewels, was a gore-covered human skeleton. It wore a crown set with diamonds, and it’s leg bones were encrusted with barnacles. A lightly glowing slug inched slowly across it’s bottom rib. 

“What the hell is that?” 

“Jashin-sama was so pleased,” the siren continued, “that he told me I should keep you. You withstood the pain of my teeth so well, and if those that fucking ship comes back for you, I’ll devour whatever stupid fuck gets in the water and bring whatever’s left over as a sacrifice to Jashin-sama.” 

It dragged itself closer to him, powerful arms flexing and pulling it’s long, trailing form around him like a snake. 

“And even if no one comes for you, Jashin-sama chose you. That means you’re to be treasured. So I’ll keep you here with the other treasure forever. You won’t like it at first, but you’ll come around. Jashin-sama’s way is the only way, it’s just that all you damn heathens can’t see it. Pain, blood, death- they make everything clear, and you’ve already shown that you can withstand pain.”

“You’re insane.”

“All the heathens say that. If Jashin-sama hadn’t told me to keep you, I’d rip your to pieces and eat you alive for disrespecting him.” It looked delighted at the very thought. “It will take a while to convince you. Jashin-sama said it would. But I am undying. I have all the time in the world.”

It ran a wet, cold hand down his cheek. _Like a caress from a corpse._

“And don’t even fucking think of trying to escape. This cave is deep underwater, and I’ve blocked the entrance with a boulder. By the time you reached it, you would be so fucking weak from lack of air, you wouldn’t be able to move it. I can’t let you leave, you see. Eventually I’m sure you’ll stay of your own accord, but I have to leave you alone sometimes, and Jashin-sama would be disappointed if you escaped.”

It didn’t matter if he stabbed it. It could regrow body parts, bleed forever, and enchant him at will with its voice. Horror spread like ice through him, and he felt the bloody eye sockets of the skull on him. The tongue, still clenched in his fist, was the only warmth to be had. 

“What’s your name,” he asked his captor. 

“Hidan,” it purred. “Forget any other names. Any stupid human you know is worthless to you now. Now it’s just Hidan and Jashin-sama.”

It grabbed his face roughly between its hands and pressed a bloody kiss to his forehead. He felt the slightest swipe of tongue licking away the salt that had dried there while he was unconscious. His heart beat faster. 

“I’ll be back soon,” it crooned, and then dove into the water and swam out of sight. 

Kakuzu wondered if he could cut this new tongue out of the siren’s head as well.


End file.
